[signin] Implement signin button in the profile creation flow

Bug: 1105865
Change-Id: Ic23584084629f6e318083d536130792752dc303a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2332630Reviewed-by: Monica Basta <msalama@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: Diana Zagidullina <dizg@google.com>
Cr-Commit-Position: refs/heads/master@{#794959}

chrome/browser/resources/signin/profile_picker/manage_profiles_browser_proxy.js

@@ -50,6 +50,9 @@ export class ManageProfilesBrowserProxy {
    * suggested theme info, once it has been retrieved.
    */
   getNewProfileSuggestedThemeInfo() {}
+
+  /** Loads Google sign in page.*/
+  loadSignInProfileCreationFlow() {}
 }
 
 /** @implements {ManageProfilesBrowserProxy} */
@@ -73,6 +76,11 @@ export class ManageProfilesBrowserProxyImpl {
   getNewProfileSuggestedThemeInfo() {
     return sendWithPromise('getNewProfileSuggestedThemeInfo');
   }
+
+  /** @override */
+  loadSignInProfileCreationFlow() {
+    chrome.send('loadSignInProfileCreationFlow');
+  }
 }
 
 addSingletonGetter(ManageProfilesBrowserProxyImpl);

chrome/browser/resources/signin/profile_picker/navigation_behavior.js

@@ -84,14 +84,7 @@ window.addEventListener('popstate', notifyObservers);
  */
 export function navigateTo(route) {
   assert([Routes.MAIN, Routes.NEW_PROFILE].includes(route));
-  history.pushState(
-      {
-        route: route,
-        step: computeStep(route),
-        isFirst: false,
-      },
-      '', route === Routes.MAIN ? '/' : `/${route}`);
-  notifyObservers();
+  navigateToStep(route, computeStep(route));
 }
 
 /**
@@ -113,7 +106,14 @@ export function navigateToPreviousRoute() {
  * @param {string} step
  */
 export function navigateToStep(route, step) {
-  // TODO(crbug.com/1063856): Add implementation.
+  history.pushState(
+      {
+        route: route,
+        step: step,
+        isFirst: false,
+      },
+      '', route === Routes.MAIN ? '/' : `/${route}`);
+  notifyObservers();
 }
 
 /** @polymerBehavior */

chrome/browser/resources/signin/profile_picker/profile_picker_app.js

@@ -11,7 +11,7 @@ import {assert, assertNotReached} from 'chrome://resources/js/assert.m.js';
 import {html, Polymer} from 'chrome://resources/polymer/v3_0/polymer/polymer_bundled.min.js';
 
 import {AutogeneratedThemeColorInfo, ManageProfilesBrowserProxy, ManageProfilesBrowserProxyImpl} from './manage_profiles_browser_proxy.js';
-import {NavigationBehavior, Routes} from './navigation_behavior.js';
+import {NavigationBehavior, ProfileCreationSteps, Routes} from './navigation_behavior.js';
 import {ensureLazyLoaded} from './profile_creation_flow/ensure_lazy_loaded.js';
 
 Polymer({
@@ -50,6 +50,11 @@ Polymer({
    * @private
    */
   onRouteChange(route, step) {
+    if (step == ProfileCreationSteps.LOAD_SIGNIN) {
+      this.manageProfilesBrowserProxy_.loadSignInProfileCreationFlow();
+      return;
+    }
+
     const setStep = () => {
       this.$.viewManager.switchView(step, 'fade-in', 'no-animation');
     };

chrome/browser/ui/webui/signin/profile_picker_handler.cc

@@ -51,6 +51,11 @@ void ProfilePickerHandler::RegisterMessages() {
       base::BindRepeating(
           &ProfilePickerHandler::HandleGetNewProfileSuggestedThemeInfo,
           base::Unretained(this)));
+  web_ui()->RegisterMessageCallback(
+      "loadSignInProfileCreationFlow",
+      base::BindRepeating(
+          &ProfilePickerHandler::HandleLoadSignInProfileCreationFlow,
+          base::Unretained(this)));
 }
 
 void ProfilePickerHandler::OnJavascriptAllowed() {
@@ -131,6 +136,11 @@ void ProfilePickerHandler::HandleGetNewProfileSuggestedThemeInfo(
   ResolveJavascriptCallback(callback_id, std::move(dict));
 }
 
+void ProfilePickerHandler::HandleLoadSignInProfileCreationFlow(
+    const base::ListValue* args) {
+  // TODO(crbug.com/1063856): Add implementation.
+}
+
 void ProfilePickerHandler::OnSwitchToProfileComplete(
     Profile* profile,
     Profile::CreateStatus profile_create_status) {

chrome/browser/ui/webui/signin/profile_picker_handler.h

@@ -28,6 +28,7 @@ class ProfilePickerHandler : public content::WebUIMessageHandler,
   void HandleLaunchSelectedProfile(const base::ListValue* args);
   void HandleAskOnStartupChanged(const base::ListValue* args);
   void HandleGetNewProfileSuggestedThemeInfo(const base::ListValue* args);
+  void HandleLoadSignInProfileCreationFlow(const base::ListValue* args);
 
   void OnSwitchToProfileComplete(Profile* profile,
                                  Profile::CreateStatus profile_create_status);